 /*******************************************************************************
  * Copyright (c) 2004, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/

 package org.eclipse.ui.internal.registry;

 import org.eclipse.core.commands.AbstractHandler;
 import org.eclipse.core.commands.ExecutionEvent;
 import org.eclipse.core.commands.ExecutionException;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.IWorkbenchWindow;
 import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.handlers.HandlerUtil;
 import org.eclipse.ui.internal.misc.StatusUtil;
 import org.eclipse.ui.statushandlers.StatusManager;

 /**
  * Command handler to show a particular view.
  *
  * @since 3.0
  */
 public final class ShowViewHandler extends AbstractHandler {
     
     /**
      * The identifier of the view this handler should open. This value should
      * never be <code>null</code>.
      */
     private final String viewId;

     /**
      * Constructs a new instance of <code>ShowViewHandler</code>.
      *
      * @param viewId
      * The identifier of the view this handler should open; must not
      * be <code>null</code>.
      */
     public ShowViewHandler(final String viewId) {
         this.viewId = viewId;
     }

     public final Object execute(final ExecutionEvent event)
             throws ExecutionException {
         final IWorkbenchWindow activeWorkbenchWindow = HandlerUtil
                 .getActiveWorkbenchWindowChecked(event);

         final IWorkbenchPage activePage = activeWorkbenchWindow.getActivePage();
         if (activePage == null) {
             return null;
         }

         try {
             activePage.showView(viewId);
         } catch (PartInitException e) {
             IStatus status = StatusUtil
                     .newStatus(e.getStatus(), e.getMessage());
             StatusManager.getManager().handle(status, StatusManager.SHOW);
         }

         return null;
     }
 }

